I was testing how torch.cat will affect the backpropagated loss. I write this piece of code but I’m not sure why no gradient will reach the inputs. any clue what might be wrong ?
x = Variable(torch.tensor([1.]), requires_grad=True) y = Variable(torch.tensor([1.]), requires_grad=True) target = Variable(torch.tensor([3., 3.])) z = torch.cat([x,y]) loss = Variable( torch.mean(z - target), requires_grad = True) loss.backward()
now I’m checking the gradient of each one of the variables x, and y but their Values are None !! what is going on
x.grad == None True y.grad == None True